1. Technical Field of the Invention
The present invention relates to a disk cartridge which includes a protective housing enclosing a rotatable recording disk of the optical or magnetic type.
2. Description of the Prior Art
Disk cartridges contemplated by this invention may be of the familiar 31/2 inch Floppy format or the more recent optical disk cartridge. The 31/2 inch Floppy disk cartridge includes a rectangular plastic shell enclosing a circular disk which is rotated during operation and accessed during operation by magnetic heads capable of recording or reading information to or from the recording disk. The housing is provided with a movable shutter which may be slid between an open position providing access of the magnetic heads to the recording disk and a closed position which seals the housing and prevents contamination of the recording disk during storage. The shutter is provided with a spring to return the shutter to the closed position when the cartridge is removed from a drive mechanism including the magnetic heads and means for rotating the recording disk.
Common problems with the shutter return spring of such cartridges are that a reliable residual force is not provided by the spring to retain the shutter in the closed position during storage and inadequate control over the spring forces produced between the shutter open and closed position. Another problem associated with disk cartridges of the type described above is that the recording disk is free to move within the cartridge during storage. This results in an objectionable rattle of the disk within the cartridge and may result in damage to the recording disk.
Optical recording disk cartridges have a similar construction to that of the 31/2 inch Floppy disk cartridges, and have the same problems described above with respect to the 31/2 inch cartridge. The present invention addresses both the magnetic and optical disk cartridge types and is applicable to any cartridge which comprises a housing having a sliding shutter and which encloses a disk which is rotated during operation.